// Copyright 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef UI_BASE_IME_CHROMEOS_COMPONENT_EXTENSION_IME_MANAGER_H_
#define UI_BASE_IME_CHROMEOS_COMPONENT_EXTENSION_IME_MANAGER_H_

#include <map>
#include <set>

#include "base/files/file_path.h"
#include "base/macros.h"
#include "base/memory/scoped_ptr.h"
#include "base/observer_list.h"
#include "ui/base/ime/chromeos/input_method_descriptor.h"
#include "ui/base/ime/ui_base_ime_export.h"

class Profile;

namespace chromeos {

// Represents an engine in component extension IME.
struct UI_BASE_IME_EXPORT ComponentExtensionEngine {
    ComponentExtensionEngine();
    ~ComponentExtensionEngine();
    std::string engine_id; // The engine id.
    std::string display_name; // The display name.
    std::string indicator; // The indicator text.
    std::vector<std::string> language_codes; // The engine's language(ex. "en").
    std::string description; // The engine description.
    std::vector<std::string> layouts; // The list of keyboard layout of engine.
    GURL options_page_url; // an URL to option page.
    GURL input_view_url; // an URL to input view page.
};

// Represents a component extension IME.
struct UI_BASE_IME_EXPORT ComponentExtensionIME {
    ComponentExtensionIME();
    ~ComponentExtensionIME();
    std::string id; // extension id.
    std::string manifest; // the contents of manifest.json
    std::string description; // description of extension.
    GURL options_page_url; // an URL to option page.
    base::FilePath path;
    std::vector<ComponentExtensionEngine> engines;
};

// Provides an interface to list/load/unload for component extension IME.
class UI_BASE_IME_EXPORT ComponentExtensionIMEManagerDelegate {
public:
    ComponentExtensionIMEManagerDelegate();
    virtual ~ComponentExtensionIMEManagerDelegate();

    // Lists installed component extension IMEs.
    virtual std::vector<ComponentExtensionIME> ListIME() = 0;

    // Loads component extension IME associated with |extension_id|.
    // Returns false if it fails, otherwise returns true.
    virtual void Load(Profile* profile,
        const std::string& extension_id,
        const std::string& manifest,
        const base::FilePath& path)
        = 0;

    // Unloads component extension IME associated with |extension_id|.
    virtual void Unload(Profile* profile,
        const std::string& extension_id,
        const base::FilePath& path)
        = 0;
};

// This class manages component extension input method.
class UI_BASE_IME_EXPORT ComponentExtensionIMEManager {
public:
    ComponentExtensionIMEManager();
    virtual ~ComponentExtensionIMEManager();

    // Initializes component extension manager. This function create internal
    // mapping between input method id and engine components. This function must
    // be called before using any other function.
    void Initialize(scoped_ptr<ComponentExtensionIMEManagerDelegate> delegate);

    // Loads |input_method_id| component extension IME. This function returns true
    // on success. This function is safe to call multiple times. Returns false if
    // already corresponding component extension is loaded.
    bool LoadComponentExtensionIME(Profile* profile,
        const std::string& input_method_id);

    // Unloads |input_method_id| component extension IME. This function returns
    // true on success. This function is safe to call multiple times. Returns
    // false if already corresponding component extension is unloaded.
    bool UnloadComponentExtensionIME(Profile* profile,
        const std::string& input_method_id);

    // Returns true if |input_method_id| is whitelisted component extension input
    // method.
    bool IsWhitelisted(const std::string& input_method_id);

    // Returns true if |extension_id| is whitelisted component extension.
    bool IsWhitelistedExtension(const std::string& extension_id);

    // Returns all IME as InputMethodDescriptors.
    input_method::InputMethodDescriptors GetAllIMEAsInputMethodDescriptor();

    // Returns all XKB keyboard IME as InputMethodDescriptors.
    input_method::InputMethodDescriptors GetXkbIMEAsInputMethodDescriptor();

private:
    // Finds ComponentExtensionIME and EngineDescription associated with
    // |input_method_id|. This function retruns true if it is found, otherwise
    // returns false. |out_extension| and |out_engine| can be NULL.
    bool FindEngineEntry(const std::string& input_method_id,
        ComponentExtensionIME* out_extension);

    bool IsInLoginLayoutWhitelist(const std::vector<std::string>& layouts);

    scoped_ptr<ComponentExtensionIMEManagerDelegate> delegate_;

    // The map of extension_id to ComponentExtensionIME instance.
    // It's filled by Initialize() method and never changed during runtime.
    std::map<std::string, ComponentExtensionIME> component_extension_imes_;

    // For quick check the validity of a given input method id.
    // It's filled by Initialize() method and never changed during runtime.
    std::set<std::string> input_method_id_set_;

    std::set<std::string> login_layout_set_;

    DISALLOW_COPY_AND_ASSIGN(ComponentExtensionIMEManager);
};

} // namespace chromeos

#endif // UI_BASE_IME_CHROMEOS_COMPONENT_EXTENSION_IME_MANAGER_H_
